Current-impulse transmitter.



1. G. ROBERTS.

CURRENT IMPULSE TRANSMITTER.

APPLICATION FILED FEB. 28. 1914.

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Wff yesses: 7% ./%t@m% JOHN G. ROBERTS, 01E DOBBS FERRY, NEW YORK, ASSIGNOB TO WESTERN ELECTRIC COMPANY, OF NEW YORK, N. Y., A CORPORATION OF ILLINQIS.

Specification of Letters Patent.

Patented Aug. 3, 1915.

Application filed February 28, 19M. Serial No. 821,718.

T 0 all whom it may concern Be it known that 1, JOHN G. ROBERTS, a citizen of the United States, residing at Dobbs Ferry, in the county of Vestchester and State of New York, have invented certain new and useful Improvements in (lurrent'lmpulse Transmitters, of which the following is a full, clear, concise, and exact description.

This invention relates to apparatus for transmitting signaling impulses suitable for the control of automatic switches of telephone exchanges. its object is the selection and transmission of code impulses.

In accordance with this invention there is provided a single commutatiiig device for sending the impulses and this device is capable of selective adjustment and operation preferably by manipulating a series of push button plungers. The. sending mechanism, may comprise switch contacts connected to a line and a source oi current'cooperating with a commutator cylinder having a plurality of insulating segments on its surface. 'lheseinsulating segments are divided into groups, any one of which is adapted to be selected, through various movements of the cylinder, to manipulate the switch contacts in a manner to transmit currents of electricity designed to make up a difi'erent combination or code of impulses for each group of segments. The cylinder may be actuated through the agency of the series of plungers, any one of which when depressed, may set 'a particular group of segments associated therewith in an operative relation to the switch contacts, and may also actuate a motor mechanism for the manipulation of the switch contacts.

ll'eretoiore in automatic telephone systems. impulses varying in number from 1 to 10 for each character or digit have been employed to call a subscribers number through suitable apparatus at central ollice.

This invention may be used in connection with a circuit closed to battery and leading to and connected with apparatus at central oliice. capable or registering and translating code impulses to call a subscriber, each digit in a subscriber s number corresponding-to a particular combination of such impulses, such a system being the subject of another application of this applicant Serial No. 778,749, filed July 12, 1913.

In this particular form of the invention two kinds of impulses are used; a full impulse produced by a full interruption of the circuit, and a partial impulse produced by a partial interruption of the circuit by means of the introduction into the circuit of a resistance shunt coil. Byvarying the order of succession of these two kinds of impulses, a code of twelve characters may be produced with a maximum of three and a minimum of two impulses for each character.

The invention will be particularly described and the various features thereof explained in detail by reference to the accompanying drawings in which:

Figure 1 is a diagrammatic layout of the commutator and a simple circuit arrangement that may be used therewith; Fig. 2 is a cross-sectional view of the mechanism taken substantially on the line 2-2 of Fig. i; Fig. is a fragmentary elevation oi the mechanism looking principally along the line 33 of Fig. 2; Fig. 4 is a fragmentary plan view of the mechanism taken of the line H of Fig. 2; Fig. 5 is a plan view of the mechanism shown in Fig. 3; Fig. 6 is a perspective view of a plunger locking plate and commutator brushes; Fig. 7 is a perspective view of one plunger and its associate parts; Fig. 8 is the bottom view of the shaft-actuating pawl and ratchet taken on the line 88 of Fig. 3.

The same letters of reference are used to designate the same parts wherever they are SllOfi/Il.

Referring to the diagram, Fig. 1, to illustrate more clearly the mechanical principles on which the inventionis based, the surface of a commutator 11 is shown laid out fiat and the separate insulating segments 12 thereon placed in their relative position. The commutator 11 is adapted by the depression of series of buttons to move, first, downward, second, a varying angular distance, third, upward and finally a continued angular distance so that when returned to normal position it has made a complete revolution. The stationary brushes or switch contacts 13, 1% and 15 therefore contact with the surface at the normal position marked N on the commutator when it is moved down-. ward, and later when moved upward they contact at a position corresponding to the particular button selected. It is this upward movement that causes the connection between the brushes to be variously interrupted by insulating segments, and there are twelve ositions marked from 0 to '9 and X and that may be placed in such operating relations to the brushes.

o impart these various movements to the commutator, I have provided a mechanism which may be' operated by a series ofplungers 16 arranged in a circular row and having buttons 17 with characters inscribed thereon so as to correspond with the figures on the face of the watch. A finger guide plate 18 is provided to guide the operators finger on the particular button depressed so that the, adjacent buttons may not be acwith guide members 32. and 33 as we as cidentally displaced during this operation.

Referring now more especially to Figs. 2 and 7, it may readil be seen that any one of these plungers w en depressed moves a' lever 19 downward, but is prevented from operating this lever a second time after having oncereturned upwardly the smallest distance. This is done by means of a spring 20 having an angular projection 21 that slips in under the'lever-actuating pawl 22 during the depression of the plunger and which therefore throws the pawl out of engagement at notch 23 the .moment the plunger starts to return upward. The pawl cannot again be placed in operative position until both the lever 19 and the plunger 16- have fully returned to normal, when thewedge 24 integral with the top supporting plate 25, forces the projection 21 from under the pawl which then again engages the notch 23 under pressure of spring 26.

Any one of the levers 19 when thus operated forces the circular locking plate '27 downwardly and is locked therewith, by means of an angular extension 28 and catch 29 at the free end of the lever which move into an aperture 30 in the plate, and by means of a slight angular movement given to the plate at this time. Integral with the plate is a downwardly extending arm 31, havin its lower portion slightly offset and strad led by two fixed guide members 32 and 33. This ofl'set portion will, therefore,

when the plate moves, be guided to impart to the plate the angular movement mentioned above, and the direction of which is 7 shown by the arrow point in Fig. 6.

The bod portion 34 of the commutator 11 is moun on the shaft 35 so that it will rotate therewith, but will have an independent vertical movement thereon, and is for that purpose keyed to the shaft by means of a pro ection 36 on thebody-portion engaging the longitudinal slot 37 in the shaft.

, disk 56 when moved b 42'for the commutator brushes 13, 14 and 15. I

The normal resting plate 41 is the segmental piece shown attached to but insulated froma the U-shaped projection 43 extendin from the lower oifs et portion of arm 31. he ofinormal resting plate 42 is the segmental piece shown attached to but insulated fromthe projection 44 inte al with plate 27 and extending downwar 1y therefrom. The brushes 13, 14 and 15 are attached to but insulated from the supportin member 45 which in turn is rigidly-scour to the frame member 46. This member 45 is inte l a plunger a varying rotary motion, then slowly return it upward and again rotate it so that it has madea complete revolution, there is provided awinding and controlling mechanism which is best illustrated in Figs.

2, 3,5 and '8, and is as follows; The commu tator has a circular rack extension 50 adapt-' been moved downward by the depression of ed to rotate the inion 51 and the double acting locking paw "52, the latter being permanently fixed to theformer in an angular relation by means of an arm 53 and a shaft 54. This locking pawl 52 engages a notch 55 in a wise direction, but wi 1, after having trav-- eled 180 degrees in that direction, bevrendered inoperative, with regard to the transmission of any further movement to the disk, b engagement with a, fixed pin 57 which isengages it from the notch 55. Integral with disk 56 is ing with a pinion 59. his pinion is adapted to rotate a pair of bevel gears 60 and 61 by bein mounted integral with gear 60 on. the shit t 62 supportedin frame 46.

the rack in a clocka Igear-wheel-58 mesh- The beveled gear 61 mounted loosely on shaft 35 is provided with a hub to which the inner end of a s iral spring 63 is attached. The other end 0 this spring is aflixed to the frame 46 so that when the beveled gear is rotated it will store up power in the spring. Disk 64, which is permanently aflixed to the hub of the beveled gear 61, carries a springmovement of the commutator and thereby placingiany other portion thereof, having different combinations olf insulating segments, in a position to combine the contacts in different sequence of operations.

When the calling subscriber closes his circuit at switchhook contact 91, all three relays 87, 88 and 93 are operated. A full interruption has no effect on relay 93 which is made slow acting, but deenergizes relays 87 and 88. A partial interruption has no efiect on relays 93 and 87, the latter beinlg what is known as a slow-release relay. elay 88,

however, will let its armature fall back, as it is made to operate only on a full currentpotential. By this arrangement of preliminary recording relays at central office, the different current combinations set up at the substation can be made to operate other automatic selecting devices associated with said relays'to eflectcommunication between the calling and the called subscriber.

What is claimed is:

1 1. In'a code impulse transmitting device, a plurality of fixed contacts, a commutator having thereon a plurality of contacts arr'anged'in groups,.a plurality of plungers, a lever associated with each of said plungers,

position a group of contacts corresponding means actuated by any one of said levers for selectively operating said commutator to to the lever actuated in operative relation to the fixed contacts, and means storing energy from said lever when operated to restore said commutator to normal, whereby the proper group of contacts thereon will engage said xed contacts.

2. In a code impulse transmitting device, a plurality of fixed contacts, a commutator having thereon a plurality of contacts arranged in groups, a plurality of plungers, a lever associated with each of said plungers, means actuated by any one of said levers for selectively operating said commutator to position a group of contacts corresponding to the lever actuated in operative relation to the fixed contacts, a locking means on each of said levers adapted to engage the corresponding plunger during the actuating stroke thereof, a releasing means adapted to disengage said locking means from the plunger during the return stroke thereof to said levers and a projection'on the commutator adapted to position a group of contacts corresponding to the lever actuated in operative relation to the fixed contacts, a locking means on each of said levers adapted to engage a corresponding plunger during the actuating stroke thereof, a releasing means adapted to disengage said locking means. from the plunger during the return stroke thereof to permit the return of the plunger to normal independently of the lever, means associated with said commutator adapted to lock'any one of said levers when actuated to "said commutator for maintaining the operative relation ofthe contacts selected on the commutator to the fixed contacts until the return thereof. to normal position, and means storing energy from the lever to restore the commutator to normal, whereby the proper group of contacts thereon will engage said fixed contacts.

4. In a code impulse transmitting device, a plurality. of fixed contacts, a commutator having thereon a plurality of contacts arranged in groups, means for selectively operating said commutator with respect to the fixed contacts to position any combination of groups of contacts in operative relation thereto, means for moving said commutator past the fixed contacts, whereby a series of impulses are sent varying in number and means connected to one of said fixed con tacts for varying the degree of strength of any or all impulses of the combination selected 5. Ina code impulse transmitting device, a plurality of fixed contacts, a commutator having thereona plurality ofv contacts'arranged in groups, a plurality of plungers, means operated by each plunger for moving said commutator longitudinally and rotat-ably into a position such that a group of contacts thereon corresponding totthe plunger actuated will be opposite said fixed contacts, and means storing energy from said plunger-s for restoring said commutator to normal position partially by a longitudinal movement, whereby the proper roup of contacts thereon will engage said xed contacts and then by a rotary movement.

6. In a code impulse transmitting device, a plurality of fixed contacts, a commutator having thereon a plurality of contacts arranged in groups, a plurality of plungers, a lever associated with each of said plunger-s for moving said commutator longitudinally, means responsive to such longitudinal movement of the commutator for the rotation thereof, means for detaining the commutator into position such that a group of contacts corresponding to the lever actuated will be opposite said fixed contacts, means responsive to the said longitudinal movement of the commutator for restoring said commu-' tator longitudinally, whereby the proper mssoo 5;

group of contacts thereon will engage said my name this 26th day of February A. D. fixed contacts and means effective at the end 1914. of the return of the commutator longitudinally for releasing said commutator from 5 the selected position allowing it to rotate Witnesses:

back to normal position. KATHERINE L. STAHL, In witness whereof, I hereunto subscribe NANON E. TUTHILL.

J OHN G. RGBERTS. 

